Electric heater.



PATENTED MAY 26, 1903.

V No. 729,369.

M. LOEWENTHAL. ELEGTRIG HEATER. APPLIOA'VI'IOVN FILED nm). 8,'1902.

6 SHEETS-SHBET 1.

NO MODEL.

No. 7295369. PATENTED MAY 26, 1903.`

u v M. LOEWENTHAL.

ELEGTEIG HEATEE.

APPLIOATIONIILED 1330. 8, 1902. V I0.MOD-BL. 5 Suns-SHEH 3.

THE uoiRs ?a ms co. PHOYO-LINU. WASHKNGTON. o. c.

PATE'NTED MAY 26, 1903.

M. LOEWENTHAL ELEGTRIC HEATEL APPLIOATION PILED DED. 8 1902.

6 SHEBTS--SHEET 4.

NO MODEL.

No. 729,369. PATENTED MAY 26, 1903. M. LOEWENTHAL.

ELECTRIC HEATER.

APPLIOATION I'ILED 10110. 8, 1902.

xo HODEL. 6 sEEETs-sHEET 5.

UNITED STATES Patented May 26, 1903.'

MAX LOEWENTHAL, OF NEW YORK, N. Y.

ELECTRIC HEATER.

SPECIFICATION formng part of Letters Patent N o. 729,369, dated May 26, 1903.

Application filed December 8. 1902. Serial No. 134.426. (No model.)

which the following is a specification, accompanied by drawings.

My invention relates to electrically-heated tools, and more particularly to that class of tools heated by means of electrieal resistance, and such classes of tools as fiat-irons and the like. a I

The objects of my invention are to improve upon such electrieally-heated irons and simplify their Construction and arrangement, with increased efciency.

Further objects of my nvention will hereinafter appear; and to these ends nyinvention consists in apparatus for carrying out the above objects constructed and arranged and having the general mode of operation substantially as hereinafter fully described in this specification and shown in the accompanying drawings, in which Figure l is a longitudinal sectionaleleva tion of one form of electric iron embodying my invention. Fig. 2 is a plan view of an insulating-strip having a conducting layer thereon and adapted for use in the heater element of the iron shown in Fg. 1. Fig. 3 is a longitudinal sectional elevation of a modified form of iron. Fg. 4: is a top plan view of the iron shown in Fig. 3, with the handle and upper plate removed. Fig. 5 is a plan View of the iron shown in Fig. l. Fig. 6 is an enlarged detail view of the attachment for the iron shown -in Fig. 1. Fig. 7 is an enlarged detail longitudinal sectional view of the heater element. Fig. 8 is a top plan view of a modified form of iron, with the top removed. Fig. 0 is a longitudinal sectional elevation, With the handle broken away, of the form of iron shown in Fig. 8. Fig. 10 is a plan view of an insulating-strip provided with a conducting l; yer and adapted for use in the heater element of iron shown in Fig. f). Fig.

ll is a top plan View of the holder for the insulating-strip provided with the conducting layer shown in Fig. 2 and in longitudinal sec-' tion in Fig. '7, and Fig. 12 illustrates in entremely thin conducting layer is provided upon an insulating-base, thereby forming a suitable electric resistance which is light and compact and of extremely high resistance. The condueting layer consists of fired liquid metal, and suitable forms of insulating-bases having 'theconducting layer of fired liquid metal are illustrated in the accompanying drawings.

i In order to illustrate my invention, I have shown and will describe what may be termed a heater element, the heating resistance of which comprises the herein-described thin layer of conducting material.

In Figs. 1 and 5 a fiat-iron is shown, with one pointed end and one blunt end. In Fig. 4, I have shown an iron in a somewhat different form; and Fig. S illustrates what may be termed a double-ender iron for heavy work. The heater element is of substantially the same Construction in these different forms of irons, but is varied to adapt it to the con- V struction of iron in each separate modification, and 'any desired form of iron used. f

I have found that the eonducting layer of fired metal should be tightly eompressed to obtain the best results for heating purposes, and the irons I have shown constructed with may be this end in View.

In Figs. 1 and 5 the base A of the iron is hollowed for the reception of the heater element, and the cover Bis adapted to be suitably Secured, as by means of screws G, to the base A. It will be seen that when the parts are assembled the cover does not rest upon the base, and provision is thus afforded for tightly pressing the heater element between IOO the base A and the cover B. This construction is provided in several of the forms of irons. In the modification shown in Fig. 9, however, the desired pressure upon the conducting layer is obtained by means of tightly securing a plate D down upon the heater element, as by means of the screws E, so that pressure from the cover B' is not necessary.

, The heater element comprises in each instance a holder F, which may be of metal and within which the remaining members of the element are placed. The edges G of the holder may be bent to better secure the parts in place, and, as shown in the drawings, the insulating-base H, of suitable material, as mica, provided *ith the conducting layer I, is placed upon the bottom of the holder, and over this another insulating-plate J, of suitable material, as mica, is placed in position. A cover-plate K, of suitable material, as nickelsteel, is then placed in position upon the insulating-plate J, and the whole forms a thin, compact heater element the conductinglayer of which forms the resistance. The shape and certain details of the Construction of the heater element may be varied as desired to adapt it to various shapes of irons.

Suitable means must be provided for conducting the current of electricity to and from the conducting layer I, and in order to utilize the conducting layer to the best possible advantage as a resistance metallic paint is spread upon the insulating-base H in a substantially U -shaped form ,as shown in the plan Views of the insulating-base. The sides of the U-shaped painted surface are separated, as shown in the drawings, by a longitudinal unpainted portion L, which may be substantially T shape, if desired, and the central end portions O of the painted surface are not provided with as heavya condncting layer as at the ends P and portions Q, for it has been found that at the points where the current enters and leaves the resistance a slightlythicker layer of low-resistance paint is used, while the same is true of the portions Q of the conducting layer.

In order that electric contact may be made between the outer terminals of the iron and the conducting layer, suitable means may be provided, shown in this instance as metallic springs R, bent into suitable form and arranged with their lower portions S in contact with the end portions P of resistance when the parts of the heater element are assembled, andby making contact from the positive and negative poles of a source of supply with the springs R it will be seen that current will enter one leg or side of the U -shaped conducting layer and leave at the other leg or side after having traversed the whole extent of the layer. Strips of tin-foil T may be inserted between the portions S of the springs R and the insulating-plates J, although these are not necessary.

The members of a heater element being assembled and inserted within the base A of an iron, a sheet U of material, such as asbestos, is placed upon the top of the element and then the cover B of the iron screwed securely to the base A, pressing the element tightly between the presser-sheet U and the base A. suitable means are provided upon the cover B of the iron for making contact with the springs R and for electric terminals to be connected to the iron, as shown in Fig. 1, the cover B being provided with metallic sockets V, suitably insulated from the iron and adapted to press upon the springs Rwhen the cover is screwed down. The cord W is provided with a suitable plug X, having terminals Y, adapted to the sockets V in the iron. As shown in this instance, the cord `W may be also provided with a flexible metallic casing Z and have means for securing the cord to the handle of the iron, and thus removably attach the plug to the iron. The handle of the iron is provided with a socket a, while a suitable securing-fiange b, adapted to the socket a, is Secured to the cord, as by means of a collar c.

The presser-sheet U has another function besides that of pressing the parts of the heater element tightly together, for it also serves to confine the heat within the iron and to the lower portion thereof. Since the top of the iron will become heated as well as the base, I construct the handle of the iron substantially as shown, forming the legs d, as well as the central portion e, of the handle hollow, and providing short struts f upon the legs dat the bottom thereof, so that there is a small contaetin g surface between the legs and the cover B of the iron, suitable screws g being utilized to secure the handle to the cover B. By this means the handle is prevented from conducting any considerable part of the heat away from the iron. The grip h may be of suitable material, as wood.

In the modified form of iron shown in Figs. 3 and 4 the cover 13 is provided with projections of plugs e' for completing circuit to the iron, contact being made, as before, between the plugs 'i and the springs R when the parts of the irons are assembled. In this construction a bottom heat 'distributing or conducting platej, such as aluminium, is shown, for better conducting the heat from the element to the base of the iron, and it will be seen that, as before, an upper presser-sheet ic, of a material such as asbestos, is used. In the modification described the coVer-plate K' of the heater element is cut away, forming a tongue K and the bottom conducting-platej is provided with apertures for the securing-screws Z. In this instance, the screws Z are arranged entirely outside of the conducting layer of heater element, so that no short-circuiting may take place. The handle of the iron is prov vided, as before, with the struts f, whereby IOO IIO

but a small surface of the handle is in contact with the cover B of the iron.

In the modification shown in Figs. 8 and 9 the heater element is Secured, as hereinbefore stated, to the base of the iron by means of suitable screws E. The base 1) in this instance is not hollowed, but consists of a fiat plate to which the hollowed or recessed cover B is Secured, as by means of screws q. Since the securing-screws E for the heater element.

pass directly through all the members of the element in order to press the sheet k and conducting layer evenly and firnly over substantially the entire extent, means must be provided for insulating the screws from the layer of conducting paint, and, as shown in Fig. 10, the apertures r for the screws are provided in the insulating-base of the conducting layer, while a strip of the base is left unpainted up to the apertures, so that there is no contact between the screws E and the conducting layer of the element. As before, the cover B' of the iron is provided with contacts shown as sockets s, adapted to make contact with the springs R when the cover and base of the iron are Secured together.

It will thus be seen that according to my invcntion a simple and effeient electric iron is constructed in which the heater element is removable, so that it may be replaced by a new one when worn out, and the parts of the irons of the same general construction are in terchangeable, which advantage is true of the elements.

Obviously some features of my invention may be used without others, and my invention may be emboded in widely-varying forms.

Therefore without limiting myself to the Construction shown and described nor enumerating equivalents, I claim, and desire to obtain by Letters Patent, the following:

1. Au electrically-heated iron, comprising a base, a removable heater element, comprising a 'flat strip of relatively high resistance conducting material, and an insulating-holder em'eloping the same, said element located within the base, a cover, contacts on said cover, and means for elcctricall y connecting said resistauce with the contacts when the base and cover are connected to each other, substantially as set forth.

2. An electrically-heated iron, comprising a body portion provided with socketed contacts, a removable rcsistance within the body of the iron, and spring-contacts connecting said resistance electrically with said socketed contacts, substantially as set forth.

3. An electrically-heated iron, comprising separable portions a removable electric resistance between the same, contacts on one of said portions, and spring-contacts cooperating therewith, and connected to the resistance, and an inclosing insulating-casing for the resistance, substantially as set forth.

4. An electrically-heated tool, comprising a base, a cover, socketed contacts, an electric resistance arranged between the base and cover, and spring-contacts in electrical connection with said resistance, and adapted to make contact with the socketed contacts, substantially as set forth.

5. An electrically-heated iron, comprising a base, a cover provided with electrical contacts extending therethrough, a removable heater element comprising a fiat strip of relatively high resistance conducting material and having eXposed terminals adapted to register with the contacts in the cover and an insulating-holderenveloping said resistance, said element being arranged between the base and body portion of the iron, the exposed terninals of the element being in electrical connection with the contacts of the cover when the parts are in operative relation.

(5. A'n electrcally-heated iron, comprising a base, a cover provided with electrical contacts extending therethrough, a removable heater element comprising a fiat strip of relatively high resistance conducting material and having exposed spring-terminals adapted to register with the contacts in the cover and an insulating-holder enveloping said resistance, said element being` arranged between the base and body portion of the iron, the exposed terminals of the element being in electrical connection with the contacts of the cover when the parts are in operative relation.

7 An electrically-heated iron, comprising separable portions one of which is provided with contacts and a *removable heater element arrang'ed between the said separable portions for heating the tool having yielding contact devices and adapted to be connected to said contacts on one of said portions, substantially as set forth.

8. An electrically heated tool provided with socketed contacts secured upon the exterior the'reof and extending to the interior of the tool and a heating element within the tool, said element provided with resilient contact-pieces adapted to register with the inner ends of said socketed contacts when the tool is in operative condition.

9. An electric heater, comprising separable portions one of which is provided with contacts, and a heater element arranged under pressure between said portions, the element comprising an insulating-base having a V conductin g layer thereon, and provided with yielding contacts for electrically connecting the condueting layer with the contacts on one of the separable portions of the heater, substantially as set forth.

lO. An electric heater, comprising a hollowed base, a removable heater element arranged therein and provided with a thin conducting layer of substantiall y U shape upon an insulating-base, an upper presser-plate, and a cover secured to the base and tightly IOO IIO

pressing the thin eondueting layer of the element between the presser-plate and the base of the heate', substantially as set forth. 11. An eleetre iron, comprising a base, a

5 'emovable heater element having separated terminals, a lower eondueting-plate, and an uppe' presser-plate, a Cover for pressing the element between the presser-plate and base, Contacts 011 the iron, and means connected to :o the heater element and eomprising elastie eonduetors for eleetrically eonneeting the element to said Contacts, substantially as set forth.

In testinony WhereOf I have signed this speeifieation in the presence of two subscrib- 5 ing witnesses.

MAX LOEWENTHAL. lVitnesses:

I-I. G. OGDEN, Jr., E. VAN ZANDT. 

